919.175260 bogs and shuts down at 40 psi

by Dean
(Pennsylvania)

919.175260 motor information plate

919.175260 motor information plate

919.175260 motor information plate
919.175260 wiring
919.175260 wiring

Hello everyone! I have a Craftsman 919.175260 that I had inherited from my father who is a retired mechanic. The compressor was in his home garage and had minimal use. I brought it to my place and connected it up.


The compressor started to build air and quit when it hit 40 psi. The motor was bogging and the belt started to squeal causing the internal motor breaker to trip.

I immediately searched the internet and found this website and followed all off the trouble shooting recommendations.

I thought the caps were bad and replaced them with no change.

I then thought that the motor was failing and took it the repair shop. The technician checked the internal parts and done a load test finding nothing wrong. He said that the motor was like new.

Next, I replaced the check valve with no success.

I then opened the head and found the reed valves had a little carbon build up in. I cleaned the reed valves well and reassembled the compressor.

The pistons and cylinder walls looked good with no scratches. I fired the motor up again and the compressor pumped up to 50 psi, and it started to bog, tripping the internal motor breaker again.

Any suggestions? I ordered new reed valves today thinking that they may be worn out and possibly causing back pressure to enter into the cylinder. One thing that I did see is a slight hair crack under the valve reed near the screw on the head. Could this be the issue? I surfed the net for a new head and it is discontinued.

Thoughts please?

Thanks
Dean

Comments for 919.175260 bogs and shuts down at 40 psi

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Nov 08, 2016
919.175260 fixed!
by: Bill

On behalf of Doug and I, you are most welcome.

Nov 07, 2016
Update-Running
by: Dean

The parts came in over the weekend and I rebuilt the pump since I had it opened. The valve reeds were rusty and the flappers were worn. I believe the problems were the valves not allowing back pressure into the cylinder as well as the motor not being wired correctly and having the power to turn the crankshaft when it hit past 40psi causing it to overheat.

I cannot figure out why this compressor ran on 120v for over close to 20 years, but my father is not an electrician either so that speak for itself. He did say that the motor bogged some while using, but he dealt with it.

I reassembled the pump and rewired the motor as everyone instructed and she purrs like a kitten.

I am glad I found the website and I would like to personally thank everyone for there input.

Regard,
Dean

Nov 03, 2016
120/240
by: Doug in s.d.ca

Dean,

Notwithstanding how it may have been wired at dad's, that's a 230 (usually means anything from 208 to 240, depending on commercial power) volt motor. With no option for 120V.

So, to make it work properly, you need to get yourself a double pole breaker and wire to that. There should also be a ground wire to the frame of the machine, for safety reasons, nothing to do with how it runs.

You may want to enlist the services of an electrician, and you certainly should pull a permit to do it, for insurance reasons.

Good luck.

Nov 03, 2016
919.175260 photos
by: Bill

Photos added.

Nov 03, 2016
Doug Wiring answer
by: dean

Doug, no I was not running 220v. I have 120 running to it. I would like to post pictures but I am unsure how to.

Thanks
dean

(Moderator - start a new post - you can add up to 4 photos then - in the post ask for them to be moved to (919.175260 bogs and shuts down at 40 psi ) and it will be done.)

Nov 02, 2016
919.175260 bogs
by: Doug in s.d.ca

According to what I found, it's 6 HP and 220V.

You are running 220 to it, right?

And, according to the manual it should be on at least a 20A circuit.

Nov 02, 2016
919.175260 bogs
by: Bill

OK, an excellent power supply. That's good too.

I've just re-read your original post, and keyed on this: "The motor was bogging and the belt started to squeal causing the internal motor breaker to trip".

If the belt is squealing, assuming it's the right tension and not misaligned, it makes that noise because the motor is still trying to turn at the normal RPM, but something is slowing the belt.

That something is probably the pump is backloading the motor.

This now concerns me: "One thing that I did see is a slight hair crack under the valve reed near the screw on the head." While a crack in the pump body shouldn't be back loading the motor, what if it is, somehow, interfering with the valve? If it were, a non-functioning valve which is reacting to growing load due to air buildup in the tank, starts to impede air flow, and that would back load the motor.

I don't have any easy answers for you. I hope another visitor may have suggestions too.

Nov 02, 2016
Power
by: Dean

Bill, I had posted a response to your question, but I guess it had not posted. The compressor is wired directly into the breaker panel (single phase 120V) with 12 gauge wire and is being fed with a 20 amp breaker. I connected it identically as to how my father had it connected it his place.

Any thoughts?
Thanks
dean

Nov 01, 2016
919.175260 bogs
by: Bill

Lots of good checks done, Dean. Well done!

Tell us all about how you are getting power to this compressor. I believe it's a 5 HP, yes?

If you are restricting power to the motor circuit in some manner, shape or form, that could cause the compressor symptoms you describe.

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